Fuel-injection system



July 31, 1928. 1,679,158

L. o. FRENCH FUEL INJECTION SYSTEM Filed April 21, 1926 INVENTOR Patented'July 31, .1938;

UNITED. STA

TES'- LOUIS O. FRENCH, MILWAUKEE, WISCONSIN.

PATENT OFFICE.

. FUEL-INJECTION SYSTEM.

Application filed April 21, 1926. Serial No. 103,561.

The invention relates to fuel injection systems, and more particularly to electricallycontrolled fuel injection systems for internal combustion engines.

6 One object of the invention is to provide,

A further object of the invention is to provide a fuel injection system wherein the control is effected through theoperation of a '15 primary circuit and the fuel-metering device is in asecondary circuit, preferably of higher voltage, said primary circuit also including a variable resistance to vary the action of the fuel-metering device so as to varythe amount I of fuel charges injected into the engine.

A further object of the invention is to associate the resistance timer and control means with a low voltage timing-and-energizing circuit-by which current of higher voltage is inducedin a secondary circuit containing the operating electromagnet'of the electrically-controlled fuel-metering device. With such a system some current is flowing inthe primar'y'winding of the induction coil 80 v at all times and the cutting out of resistance enables this current to build up rapidlynt the desired time and thus improve the 1nductive' effect .of the secondary winding which, because of, its higher voltage, pro- 85 duces a quick action of the operating magnet of the metering device at the desired time.

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conf clusion hereof.

Fig. 1 is a view showing a system embodying the invention.

Fig. 2.is a detail sectional view of-a fuel; metering device for use in the system;

Fig. 3 is amodified form of the system shown in Fig. 1.

In Fig. 1, the timing control means is an engine-controlled variable resistance '5, which is more particularly shown an d*described inmy application Serial No. 170,-

328, filed Feb. 23, 1927, being a continuation in part of myapplication Serial No. 99,325,

filed April 2, 1926, and is preferably-of the pressure type wherein the resistance material, either in disk or powdered form, is L mounted in a casing 6 of insulating material and is acted upon by a thrust member 7 which may be moved directly by a timing cam 8 but preferably through a lever9 interposed between said cam and the insulated head 10 of the member7, a; spring 11 serv- '-ing to hold said lever in engagement with said cam. The lever 9 is pivotally mounted at 12 upon a support 13. rotatable relative to said cam to advance or retard the time of cutting out of resistance,'as shown in said application, and the cam 8 is preferably shdably mounted on a shaft 15, either driven by the engine or rotated in cyclic synchronism therewith. The casing 6 is secured to posts 16 on the support 13 by bolts 17 which are nsulated from said posts.

The electromagnetically-controlled fuelmetering device may be of any suitable form and 1n Fig. 1 l have shown it as a fuel-com trol valve. This valve-is herein shown, for the purpose of illustration, as alfuel injector valve 18 mounted in the engine cylinder 32, but the present invention is not limited to th s arrangement, as fuel regulation or metering may be obtained by having the electromagnetically-operated valve function as a suction or by-pass valve of a pump or as a valve 111 the discharge line of the pump as sooiated with a fuel injector valve. The electromagnetically-operated fuel-metering-andcontrol valve may be of any suitable construction and as an example of one formreference is here made to my co-pendingappggzgtion Serial No. 84,102, filed Jan. 27,

The metering device shown in Fig. 2 is one wherein the electromagnet operates the expressing member 33- of a fuel pump 34, and due to the varying of the current passmg through said operating ma net varies the amount of fuel supp-lied tothe fuel inector (not shown) associated with the engine cyhnden. The pump 34 has a suction valte 36 urged to its seat byra spring 37 and a discharge valve 38 urged to its seat by a spring 39, the pump receiving fuel through apipe 40 connected with a supply tank or priming pump and discharging it through the pipe '41 connected to the fuel injector. The member 33 is connected to a. solenoid creasing the air gap between these parts for a relatlvely long movement of the plunger 42. A shoulder 33' is provided on the nonmagnetic plunger so as to just prevent contact between said plunger and said stop when said plunger is at the end of its expressing stroke and thus prevent the possibility of freezing. The plungers 33 and 42 are moved on their expressing stroke by the, energization of the solenoid and on their suction stroke by a spring 47 interposed between a shoulder 48 on the plunger and the shell 45, and an adjustable stopscrew 49 mounted in a fixed support 50 limits the outward movement of said lungers.

In the arrangement shown in Fig. 1, the resistance timer 5 is included in a primary control circuit and the operating magnet for the metering device in a secondary circuit. The primary circuit includes a battery 62 grounded at one side at 63 and connected by a conductor 64 to one terminal of the primar winding 65 of an induction coil 66, the ot 161' terminal of said winding being connected by a conductor 67 with one terminal of the timer 5 whose other terminal is grounded at 68. A manually-operated cutout switch 62' is provided in the conductor 64. v The secondary circuit includes the secondary winding 69 of the induction coil, grounded at 70 and connected by a conductor 71 with the driven brush 72 of the distributor 73, a variable resistance 74 being shown associated with the conductor 71, though such resistance may be included in the primary circuit and in each case modify the effect of the timer resistance. The distributor brush 7-2 cooperates with. cont-acts 75 to respectively distribute the current to the metering devices by conductor 60, as in the first construction, said devices being grounded at 61. The brush 72 may ride'on the contacts 75 which are preferably of a length to provide contact with said brush during the period of low current flow in the primar circuit, or said brush may be spaced a slight distance from said contacts so that where high tension current is used in the secondary cii'cuit such current will jump the small air gap to complete the circuit through as metering device.

With 'this construction the cam 8 periodically acts to cut out resistance from the primary circuit and at sucha time as it is desired to have the metering device function, and thereupon, due to the rapid change in voltage, current is induced in the secondary circuit and preferably of a higher voltage, and while the brush 72 is operatively associated with one of the contacts 75 and. under these conditions current flows through the control magnet of the metering device to cause its operation. While but a single control has been provided in the primary circuit for controlling all the me-' tering devices, it will, of course, be under stood that a separate resistance and inductlon 0011 may be associated with each metermg concept of the invention.

device without departing'from the broad In either arrangement the timing cam 8 may have rotary motion alone so that as the speed of the engine increases the time during which resistance is cut out to permit the metering device to operate decreases, but I a prefer to provide a greater range of adjustment of the timing period and/or the amount of resistance periodically cut out of the control circuitby providing a cam of varying contour, such as those shown and described in said application Serial No. 99325, it being noted that where the metering device is a control valve associated with the supply side of the 'pump the period durlng WlllCh the valve is held open is the prime factor and that the varying of .the

.amount of resistance cut out produces a variable lift of the valve 26 or a variable stroke of the member 33, and is more par.-

ticularly of advantage where the control nected by a conductor 79 to contact 80 ofswitch mechanism 80', suitablyinsulated from a supporting casing 81 and cooperat- 111g wlth contact 82 pivoted at 83 to the casing 81 and grounded at 84, and the other side of the battery is connected by conductor 85 to brush 86 bearing on a switch arm '87 of a variable resistance 88 and engaging the resistance element 89 connected by conductor 90 with the primary winding 91 of an induction .coil" 92, which winding is grounded at 93, thus completing the primary circuit when. the contacts 80 and 82 are engaged. The secondary circuit includes the secondary winding 94, grounded at 95 and connected by conductor. 96 to the rotating distributor brush 97 operatively associated with contacts 98 of the distributor,

each of said contacts beingrespectively connected by a conductor 100 to the energizing coil of one of the metering devices 18 (only one being shown) the other side of said coil being grounded at 101, thus (501111,

oneof the contacts 98 are in cooperative on a shaft 103 driven by the engine, and a spring 104 moves a part 105 on said contact 82 against said cam and when the relief 106 moves past said part the spring 104 moves the contact 82 into engagement with thefixed contact 80.

The casing 81 may be turned relative to the cam 102 to advance or retard the time of operation, and for a more detailed showing of switch mechanism useable in this system reference may be had to my copenda ing applicationSerial No. 26,676, filed Apr.

- 29, 1925, and Serial No. 88,406, filed Feb.

The switch arm 87, may be manually or governor-operated and as here shown is suitably insulated from its shaft 107, -pivoted on a fixed support 108, and from an arm 109 connected with said shaft and having a forked end with suitable projections engaging in the annular groove of collar 110 of .a governor-111 mounted on a shaft 112 driven by the engine. A more detailed showing. of the variable resistance associated with a governor will be found inmy copending application Serial No. 88,406, previously mentioned.

In the arrangement shown in Fig. 3, during the time the primary circuit is closed and the brush 97 is passing over one 'of the contacts 98 current will flow in the secondary circuit and energize the operating magnet of the metering device associated with this contact, and by varying'the position of the switch arm 87 the strength of primary current will be varied and hence the secondary current will be varied, and hence the action of the operating magnet will be varied and thus varying amounts of fuel charges will be delivered to the engine cyl inder. Thus, where the meteringdevice is a control valve in the discharge line of the fuel pump or is 'theplunger of the pump, varythe resistance will va the lift of said va ve or the stroke of sand pump to v ary the amount of fuel supplied to the engine, and where the resistance is controlled by a speed-responsive device, such as the govegior 11 1,the resistance may vary with the Y s d of. the engine or effect agradual reduction of fuel charge as the speed increases, or said resistance may be maintained colithereby.

stant through a predetermined" speed range and then through governor action vary,

above said speed until'in either case when 'a predetermined maximum speed is reached the resistance then included inthe circuit is so great that not enough current will be induced in the secondary circuit. when the contacts and 82 are engaged to cause the operating magnet of the meteringdevice to liftthe valve or move the pump plunger, and hence the supply of fuel to the engine is predetermined maximum.

I desire it to be understood that this -in-- vention is not to be limited to any particular form or arrangement of parts except inv interrupteduntil the speed drops .below'the so faras such limitations are s pecified in the claims or necessitated by the prior art; What I claim as my invention is:

1. In a fuel injection system for internal combustion engines, the combinationof a primary control circuit including a variable resistance, a secondary circuit inductively associated with said primary circuit and periodically influenced threby in cyclic syn? chronism with the en ine, an electromagnefl ically controlled fue -mete ring,,device controlling the amount of fuel deliveredtothe engine and having its controlelectromagnet included in said secondary circuit, and means for varying said resistance to vary the action of said control electromagnet and thus cause said metering device to vary the amount of fuel charges delivered to the engine. ,4 I

ing device having its control electromagnet inductively associated with said primary circuit and controlled thereby.

4. In a fuel injection system, the combination with a primary control circuit including a varlable resistance, a variable engine-com y trolled means for periodically varying'said resistance, and an electromagnetically-conloo 2. In a fuel injection system, the combinatrolled fuel-metering device having its con trol .electromagnet inductively associated with said primary circuit and controlled 5; In a fuel injection system, the combination with a primary circuit, means for periodically varying the intensity of current in g k fuel-metering device having acontrol electromagnet in said secondary circuit in-* fluenced bysaid primary circuit to operate said metering device on the periodic in- 5 crease of current in the primary circuit.

6. Ina fuel injection system, the combination with a primary circuit, means for periodically varying the intensity of current in 1 said circuit, a secondary circuit inductively 10 associated with said primary circuit, a fuelture.

metering device having a control electromagnet in said secondary circuit and influenced by said primary circuit to operate said metering device on the periodic increase of circuit in the primary circuit, and means for varying the amount of periodic increase of the current.

In testimony whereof, I' affix my signa- LOUIS 0. FRENCH. 

